Phosphates affect invasiveness of Lemna minuta

Aquatic Botany paper by Simona Paolacci

PhD student Simona Paolacci has published a paper entitled “A comparative study of the nutrient responses of the invasive duckweed Lemna minuta and the native, co-generic species Lemna minor” in the journal “Aquatic Botany” (Paolacci, S., Harrison, S. and Jansen, M.A.K, 2016. Aquatic Botany, 134, pp.47-53).

Lemna minuta (left) and Lemna minor (right)
Lemna minuta (right) and Lemna minor (left)

Simona is working to elucidate the reasons behind the invasiveness of the alien duckweed Lemna minuta in Ireland, as well as major parts of Europe. This American species was first detected in France in 1965. It has now spread throughout much of Europe, often displacing native Lemna minor. One hypothesis to explain the success of alien species in general is that these species are capable of taking advantage of changing environments. In this study Simona tested whether nutrient enrichment of surface waters (eutrophication) favours the alien Lemna minuta over native Lemna minor. A key finding of the study is that Lemna minuta outgrew Lemna minor under conditions of high phosphate supply, while Lemna minuta grew less than Lemna minor when phosphate concentrations in the growth medium were low. Thus, eutrophication is potentially facilitating the invasion of European surface waters by alien Lemna minuta.

Simona Paolacci

Simona’s PhD project is funded by the Irish Research Council (IRC), and jointly supervised by Prof. Marcel Jansen and Dr. Simon Harrison.